thegeocachekids
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Question about How Does a Chick Breathe Inside its Shell expt

Postby thegeocachekids » Wed Feb 10, 2016 7:14 pm

My daughter just collected all her data for the experiment "How Does a Chick Breathe Inside its Shell?" But I have a question about her results-- she has consistency between eggs from different species (store bought chicken eggs, farm fresh chicken, duck and turkey eggs) in that the "fresh" eggs all incorporated more dye then when we saved half of them in the fridge for 2 weeks and then placed them in dye. But we had expected, based on a discussion with the farm owner we purchased fresh eggs from that "aged" eggs- those we had saved in the fridge for a week- should incorporate more dye because the porosity of the shell increases both over time and due to refrigeration. But in the 4 different egg types we tried, with multiple eggs per batch, this never held true. She'll report her results but is it accurate that porosity should increase? Is it possible the egg pores closed when removed from the fridge and placed in the dye at room temp for 24 hours? Is it accurate that porosity should increase? To do a little more research she has now placed some eggs in dye in the fridge and we're leaving them in for a whole week. Thanks for any thoughts on this subject.

mhoch888
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Re: Question about How Does a Chick Breathe Inside its Shell expt

Postby mhoch888 » Wed Feb 10, 2016 9:56 pm

thegeocachekids wrote:My daughter just collected all her data for the experiment "How Does a Chick Breathe Inside its Shell?" But I have a question about her results-- she has consistency between eggs from different species (store bought chicken eggs, farm fresh chicken, duck and turkey eggs) in that the "fresh" eggs all incorporated more dye then when we saved half of them in the fridge for 2 weeks and then placed them in dye. But we had expected, based on a discussion with the farm owner we purchased fresh eggs from that "aged" eggs- those we had saved in the fridge for a week- should incorporate more dye because the porosity of the shell increases both over time and due to refrigeration. But in the 4 different egg types we tried, with multiple eggs per batch, this never held true. She'll report her results but is it accurate that porosity should increase? Is it possible the egg pores closed when removed from the fridge and placed in the dye at room temp for 24 hours? Is it accurate that porosity should increase? To do a little more research she has now placed some eggs in dye in the fridge and we're leaving them in for a whole week. Thanks for any thoughts on this subject.

Hi! Cool experiment. :mrgreen: From what I've briefly read online, the farmer is correct- porosity should increase in the refrigerator ["at low temperatures, the outer mucoprotein cuticle (which behaves like wax) covering the shell dries and shrinks, exposing the some 17,000 pores in the calcium carbonate shell" - possibly unreliable reference]. By the way, nice work following up with that control experiment. You are true scientists!

My only explanation for this unexpected result is that perhaps the environment in the fridge was very humid, and because there was a lot of water vapor in the air, the eggs ended up absorbing a lot of water. Then when your daughter put them in the dye, since they'd already absorbed so much water, they couldn't absorb much more. The "fresh" eggs may have started out drier, so they absorbed more dye. If this is true, I'd expect that your follow-up experiment of exposing the eggs to dye inside the fridge will not change the result. They'll still absorb less dye than fresh eggs.

Anyway, that's just a random idea. Sounds like you're both very on top of the experiment and regardless of the exact results, the project seems to be a success!

Megan


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